Twin-Roll Blocking Unit for Switching Device Triggering

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Solution Overview

Problem

Existing tripping mechanisms for switching devices require high release forces, leading to complex and expensive manufacturing processes, and are prone to unintentional unlatching due to high friction and tolerance issues.

Innovation Solution

A tripping mechanism with a drive lever, a mechanical energy storage device, and a locking system featuring a first and second roller, a second locking element, and a triggering element, which allows for secure holding in the 'on' position and quick transition to the 'off' position by reducing the force required for unlatching through a mechanical energy storage device like a compression spring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple locking mechanism with bolt and lever is used, then the device complexity is reduced, but the release force required increases to about 100 N

Engineering Contradiction:
Improvelocking mechanism complexityVSAvoidrelease force
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The locking mechanism is divided into two independent locking elements (first locking element on drive lever, second locking element on lever) that work simultaneously. Each locking element engages with a corresponding roller, distributing the locking function across multiple points and reducing the force required at each individual point while maintaining overall security.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking mechanism transitions from a single-point linear lock to a multi-point distributed lock involving two locking elements and two rollers. This dimensional expansion in the locking architecture allows for more efficient force distribution and reduces the peak release force required.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If small tolerances are used to prevent unintentional unlatching, then the reliability improves, but the friction increases leading to higher release forces

Engineering Contradiction:
Improveunintentional unlatching preventionVSAvoidfriction force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent extracts the friction problem from the tolerance control function. Instead of relying on tight tolerances to prevent unintentional unlatching, the mechanism uses a triggering element that actively disengages the locking elements from the rollers. This separates the reliability function (preventing accidental release) from the friction issue, allowing larger tolerances without increasing friction-related release forces.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The triggering element acts as an intermediary that mediates between the locking elements and the rollers. By introducing this intermediate component, the system can maintain reliable locking without requiring tight tolerances, as the triggering element provides a controlled disengagement path that overcomes friction without requiring excessive force.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If high release forces are required, then the latching is secure, but the manufacturing cost increases due to custom-made triggering magnets and strong springs

Engineering Contradiction:
Improvelatching securityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the force parameter by distributing the locking function across two locking elements and two rollers. This parameter change in the force distribution allows the use of standard, off-the-shelf triggering magnets and springs instead of custom-made high-force components, reducing manufacturing costs while maintaining secure latching through the distributed locking architecture.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If high release forces are required, then the latching is secure, but the construction must be solid and components strong, increasing device complexity

Engineering Contradiction:
Improvelatching securityVSAvoidconstruction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is segmented into two independent locking elements and two rollers, each handling a portion of the locking function. This segmentation allows for simpler, less robust individual components compared to a single high-force locking mechanism, reducing overall construction complexity while maintaining secure latching through the distributed architecture.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The mechanism simplifies production, reduces costs, and minimizes unintentional triggering by lowering the force needed for mechanical unlocking to less than 50N, enhancing reliability and ease of manufacturing while maintaining secure latching and unlatching functionality.

Implementation Method 1

a mechanical energy storage device (115) which is suitable for acting on the drive lever (112)

Methodology Applied
Scientific EffectMechanical energy storage: Spring

Implementation Method 2

a lever (113) with a first roller (1111) and a second roller (1110), which are rotatably mounted on the lever (113)

Methodology Applied
Scientific EffectRolling friction: Roller

Data Source

PatentEP3332411B1Twin-roll blocking unit for a triggering mechanism for a switching device
Publication Date: 2019.07.24 SIEMENS AG
  • EP3332411B1 patent drawingFigure 1
  • EP3332411B1 patent drawingFigure 2
  • EP3332411B1 patent drawingFigure 3

AI summary

The invention relates to a triggering mechanism for a switching device, in particular for low-voltage devices and systems, medium-voltage devices and systems, and/or high-voltage devices and systems, the lever being equipped with two rolls for blocking purposes.